Surgical laser systems and laser lithotripsy techniques

ABSTRACT

A surgical laser system ( 100 ) includes a first laser source ( 140 A), a second laser source ( 140 B), a beam combiner ( 142 ) and a laser probe ( 108 ). The first laser source is configured to output a first laser pulse train ( 144, 104 A) comprising first laser pulses ( 146 ). The second laser source is configured to output a second laser pulse train ( 148, 104 B) comprising second laser pulses ( 150 ). The beam combiner is configured to combine the first and second laser pulse trains and output a combined laser pulse train ( 152, 104 ) comprising the first and second laser pulses. The laser probe is optically coupled to an output of the beam combiner and is configured to discharge the combined laser pulse train. 
     In some embodiments, a surgical laser system includes a laser generator ( 102 ), a laser probe ( 108 ), a stone analyzer ( 170 ), and a controller ( 122 ). The laser generator is configured to generate laser energy ( 104 ) based on laser energy settings ( 126 ). The laser probe is configured to discharge the laser energy. The stone analyzer has an output relating to a characteristic of a targeted stone ( 120 ). The controller comprises at least one processor configured to determine the laser energy settings based on the output. 
     In some embodiments of a method of fragmenting a targeted kidney or bladder stone, a first laser pulse train ( 144 ) comprising first laser pulses ( 146 ) is generated using a first laser source ( 140 A). A second laser pulse train ( 148 ) comprising second laser pulses ( 150 ) is generated using a second laser source ( 140 B). The first and second laser pulse trains are combined into a combined laser pulse train ( 152 ) comprising the first and second laser pulses. The stone is exposed to the combined laser pulse train using a laser probe ( 108 ). The stone is fragmented in response to exposing the stone to the combined laser pulse train. 
     In some embodiments of a method of fragmenting a targeted kidney or bladder stone, an output relating to a characteristic of the targeted stone ( 120 ) is generated using a stone analyzer ( 170 ). Embodiments of the characteristic include an estimated size of the stone, an estimated length of the stone, an estimated composition of the stone, and a vibration frequency measurement of the stone. Laser energy settings ( 126 ) are generated based on the output. Laser energy ( 104 ) is generated using a laser generator in accordance with the laser energy settings. The stone is exposed to the laser energy using a laser probe ( 108 ). The stone is fragmented in response to exposing the stone to the laser energy. 
     In some embodiments of a method of fragmenting a targeted kidney or bladder stone ( 120 ), the stone is exposed to first laser energy ( 130 ) having a first power level using a laser probe ( 108 ). The stone is exposed to second laser energy ( 164 ) having a second power level using the laser probe, wherein the second power level is higher than the first power level. The stone is fragmented in response to exposing the stone to the second laser energy.

BACKGROUND

Embodiments of the present invention generally relate to surgical lasersystems, laser pulse trains produced by such systems, and methods ofperforming laser lithotripsy using the systems and laser pulse trains.

Medical lasers have been used in various practice areas, such as, forexample, urology, neurology, otorhinolaryngology, general anestheticophthalmology, dentistry, gastroenterology, cardiology, gynecology, andthoracic and orthopedic procedures. Generally, these procedures requireprecisely controlled delivery of laser energy as part of the treatmentprotocol.

The treatment of kidney or bladder calculi or stones, Lithotripsy, iscurrently achieved through either ESWL (extra-corporal sound wavelithotripsy), surgery, or use of a laser (laser lithotripsy). In thelaser application, a holmium doped yttrium aluminium garnet (Ho:YAG)laser rod, or a thulium doped yttrium aluminium garnet (Tm:YAG) laserrod are used to produce laser energy having a wavelength of around2000-2100 nm to break up stones of all types. The laser energy istypically in the form of a train of laser pulses, each having long pulsewidths, such as approximately a few hundred microseconds. It is believedthat a thermo-mechanical mechanism of action is in play for breaking upthe stones, namely the laser energy superheats water in the vicinity ofthe stone, and creates a vaporization bubble. The vaporization bubblethen expands and destabilizes the stone, causing it to fragment.

There is a continuous demand for improvements to laser lithotripsyprocedures including improved fragmentation of the stones, for example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an exemplary surgical laser system inaccordance with embodiments of the invention.

FIG. 2 is a simplified illustration of an exemplary laser lithotripsyprocedure in accordance with embodiments of the invention.

FIG. 3 is a chart illustrating an exemplary laser pulse train inaccordance with embodiments of the invention.

FIG. 4 is a schematic diagram of a laser generator in accordance withembodiments of the invention.

FIGS. 5 and 6 are charts illustrating exemplary laser pulse trains inaccordance with embodiments of the invention.

FIGS. 7-9 are flowcharts illustrating methods of fragmenting a kidney orbladder stone in accordance with embodiments of the invention.

SUMMARY

Embodiments of the invention generally relate to surgical laser systems,laser pulse trains produced by such systems, and methods of performinglaser lithotripsy procedures using the systems and the laser pulsetrains. In some embodiments, a surgical laser system (100) includes afirst laser source (140A), a second laser source (140B), a beam combiner(142) and a laser probe (108). The first laser source is configured tooutput a first laser pulse train (144, 104A) comprising first laserpulses (146). The second laser source is configured to output a secondlaser pulse train (148, 104B) comprising second laser pulses (150). Thebeam combiner is configured to combine the first and second laser pulsetrains and output a combined laser pulse train (152, 104) comprising thefirst and second laser pulses. The laser probe is optically coupled toan output of the beam combiner and is configured to discharge thecombined laser pulse train.

In some embodiments, the first laser pulses are temporally offset fromthe second laser pulses in the combined laser pulse train. In someembodiments, the first laser pulses alternate with the second laserpulses in the combined laser pulse train. In some embodiments, a pulsewidth (134) of the first laser pulses and the second laser pulses is inthe range of 0.1-10,000 ns, 1 ns-500 μs, or 1 μs-10 ms. In someembodiments, the combined laser pulse train has a pulse repetition ratein the range of 1 Hz-2 GHz, or 0.1 Hz-10 GHz. In some embodiments, thefirst laser pulses each have a first wavelength, the second laser pulseseach have a second wavelength, and the first and second wavelengths aredifferent. In some embodiments, the system includes a delay generator(154) configured to delay discharge of the second laser pulse train(148) from the second laser source (140B) relative to the discharge ofthe first laser pulse train (144) from the first laser source (140A).

In some embodiments, a surgical laser system includes a laser generator(102), a laser probe (108), a stone analyzer (170), and a controller(122). The laser generator is configured to generate laser energy (104)based on laser energy settings (126). The laser probe is configured todischarge the laser energy. The stone analyzer has an output relating toa characteristic of a targeted stone (120). The controller comprises atleast one processor configured to determine the laser energy settingsbased on the output.

In some embodiments, the laser energy comprises a train (130) of laserpulses (132), and the laser energy settings include settings for a pulsewidth of the laser pulses, a pulse repetition rate of the laser pulses,a power of the laser pulses, a wavelength of the laser pulses, and/or aduration of the train of the laser pulses. In some embodiments, thesystem includes memory (124) comprising a mapping (172) of laser energysettings to values of the output, wherein the controller controls thelaser generator based on the laser energy settings of the mappingcorresponding to the output. In some embodiments, the characteristic isan estimated size of the stone, an estimated length of the stone, anestimated composition of the stone and/or a vibration frequency of thestone. In some embodiments, the output from the stone analyzer is animage of the stone, a laser induced vibration measurement of the stone,and/or a spectrometer reading of the stone. In some embodiments, thestone analyzer comprises an imager (174) configured to output an imageof the targeted stone, and the controller is configured to estimate alength of at least one dimension of the stone based on the image, andcontrol the laser generator based on the laser energy settingscorresponding to the length estimate in the mapping. In someembodiments, the stone analyzer comprises a Laser Doppler Vibrometer(182) configured to measure a vibration frequency of the targeted stone,and the controller is configured to control the laser generator based onthe laser energy settings corresponding to the measured vibrationfrequency in the mapping. In some embodiments, the stone analyzercomprises a laser induced breakdown spectrometer (184) configured tooutput a spectrometer reading indicative of a composition of thetargeted stone, and the controller is configured to control the lasergenerator based on the laser energy settings corresponding to thespectrometer reading in the mapping.

In some embodiments of a method of fragmenting a targeted kidney orbladder stone, a first laser pulse train (144) comprising first laserpulses (146) is generated using a first laser source (140A). A secondlaser pulse train (148) comprising second laser pulses (150) isgenerated using a second laser source (140B). The first and second laserpulse trains are combined into a combined laser pulse train (152)comprising the first and second laser pulses. The stone is exposed tothe combined laser pulse train using a laser probe (108). The stone isfragmented in response to exposing the stone to the combined laser pulsetrain.

In some embodiments of the method, the first and second laser pulsetrains are combined such that the first laser pulses are temporallyoffset from the second laser pulses. In some embodiments, the firstlaser pulses are temporally offset from the second laser pulses bydelaying the generation of the second laser pulse train relative to thegeneration of the first laser pulse train.

In some embodiments of a method of fragmenting a targeted kidney orbladder stone, an output relating to a characteristic of the targetedstone (120) is generated using a stone analyzer (170). Embodiments ofthe characteristic include an estimated size of the stone, an estimatedlength of the stone, an estimated composition of the stone, and avibration frequency measurement of the stone. Laser energy settings(126) are generated based on the output. Laser energy (104) is generatedusing a laser generator in accordance with the laser energy settings.The stone is exposed to the laser energy using a laser probe (108). Thestone is fragmented in response to exposing the stone to the laserenergy.

In some embodiments, the laser energy comprises a train (130) of laserpulses (132). In some embodiments, the laser energy settings includesettings of a pulse width of the laser pulses, a pulse repetition rateof the laser pulses, a power of the laser pulses, a wavelength of thelaser pulses, and/or a duration of the train of the laser pulses.

In some embodiments of a method of fragmenting a targeted kidney orbladder stone (120), the stone is exposed to first laser energy (130)having a first power level using a laser probe (108). The stone isexposed to second laser energy (164) having a second power level usingthe laser probe, wherein the second power level is higher than the firstpower level. The stone is fragmented in response to exposing the stoneto the second laser energy.

In some embodiments, the stone is exposed to the second laser energyafter exposing the stone to the first laser energy. In some embodiments,the stone is exposed to the second laser energy after the exposure ofthe stone to the first laser energy begins. In some embodiments, thefirst laser energy comprises a laser pulse train (130) having a pulserepetition rate in the range of approximately 1 kHz-2 GHz. In someembodiments, the second laser energy comprises a single laser pulse(164). In some embodiments, the second laser energy comprises a laserpulse train.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not indented to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter. The claimed subject matter is not limited to implementationsthat solve any or all disadvantages noted in the Background.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Embodiments of the present invention generally relate to surgical lasersystems, laser pulse trains produced by such systems, and methods ofperforming laser lithotripsy procedures using the systems and the laserpulse trains. Embodiments of the invention are described more fullyhereinafter with reference to the accompanying drawings. The variousembodiments of the invention may, however, be embodied in many differentforms and should not be construed as limited to the embodiments setforth herein. Rather, these embodiments are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the invention to those skilled in the art. Elements that areidentified using the same or similar reference characters refer to thesame or similar elements.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

It will be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, if an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. Thus, a first element could be termed a secondelement without departing from the teachings of the present invention.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

As will further be appreciated by one of skill in the art, the presentinvention may be embodied as methods, systems, and/or computer programproducts. Accordingly, the present invention may take the form of anentirely hardware embodiment, an entirely software embodiment or anembodiment combining software and hardware aspects. Furthermore, thepresent invention may take the form of a computer program product on acomputer-usable storage medium having computer-usable program codeembodied in the medium. Any suitable computer readable medium may beutilized including hard disks, CD-ROMs, optical storage devices, ormagnetic storage devices.

The computer-usable or computer-readable medium referred to herein as“memory” may be, for example but not limited to, an electronic,magnetic, optical, electromagnetic, infrared, or semiconductor system,apparatus, device, or propagation medium. More specific examples (anon-exhaustive list) of the computer-readable medium would include thefollowing: an electrical connection having one or more wires, a portablecomputer diskette, a random access memory (RAM), a read-only memory(ROM), an erasable programmable read-only memory (EPROM or Flashmemory), an optical fiber, and a portable compact disc read-only memory(CD-ROM). Note that the computer-usable or computer-readable mediumcould even be paper or another suitable medium upon which the program isprinted, as the program can be electronically captured, via, forinstance, optical scanning of the paper or other medium, then compiled,interpreted, or otherwise processed in a suitable manner, if necessary,and then stored in a computer memory.

The invention is also described using flowchart illustrations and blockdiagrams. It will be understood that each block (of the flowcharts andblock diagrams), and combinations of blocks, can be implemented bycomputer program instructions. These program instructions may beprovided to a processor circuit, such as a microprocessor,microcontroller or other processor, such that the instructions whichexecute on the processor(s) create means for implementing the functionsspecified in the block or blocks. The computer program instructions maybe executed by the processor(s) to cause a series of operational stepsto be performed by the processor(s) to produce a computer implementedprocess such that the instructions which execute on the processor(s)provide steps for implementing the functions specified in the block orblocks.

Accordingly, the blocks support combinations of means for performing thespecified functions, combinations of steps for performing the specifiedfunctions and program instruction means for performing the specifiedfunctions. It will also be understood that each block, and combinationsof blocks, can be implemented by special purpose hardware-based systemswhich perform the specified functions or steps, or combinations ofspecial purpose hardware and computer instructions.

FIG. 1 is a schematic diagram of an exemplary surgical laser system 100,and FIG. 2 is a simplified illustration of an exemplary laserlithotripsy procedure on a stone using the system 100, in accordancewith embodiments of the invention. In some embodiments, the system 100comprises a laser generator 102 that generates laser energy 104. In someembodiments, the laser energy 104 is optically coupled to a waveguide106, such as an optical fiber, and discharged from a laser probe 108 toperform a desired procedure, such as tissue ablation or urinary orkidney stone fragmentation.

In some embodiments, the laser generator 102 comprises one or moreconventional laser sources, such as laser resonators, that produce thelaser energy 104 having desired properties. In some embodiments, thesystem 100 produces the laser energy 104 in the form of a pulse traincomprising pulses having a relatively short pulse width and at arelatively high pulse repetition rate, as compared to laser systems ofthe prior art, particularly those used in laser lithotripsy procedures.In some embodiments, the laser generator 102 includes Q-switched laserrods to produce the laser energy 104, such as, for example, a holmiumdoped yttrium aluminium garnet (Ho:YAG) laser rod, a thulium dopedyttrium aluminium garnet (Tm:YAG) laser rod, or other conventional laserrod suitable for producing the desired laser energy 104.

The laser probe 108 may be configured to discharge the laser energy 104along a longitudinal axis 110 of the probe through a distal end 112, asshown in FIG. 2, laterally relative to the longitudinal axis of theprobe 108 (side-fire laser probe), as indicated by the arrow 114, ordischarge the laser energy 104 in another conventional manner. The laserprobe 108 may be supported in a cystoscope or endoscope 116, a distalend of which is illustrated in FIG. 2.

In some embodiments, the system 100 includes a secondary probe 118, adistal end of which is illustrated in FIG. 2. The secondary probe 118may be used, for example, to capture images of a targeted stone 120, orperform other functions. In some embodiments, the probe 118 may be usedto obtain one or more characteristics of the targeted stone 120, asdiscussed below.

In one embodiment, the system 100 includes a controller 122 thatincludes one or more processors that are configured to execute programinstructions stored in memory 124, or other location, to carry outvarious functions described herein. In some embodiments, the controller122 controls the laser generator 102 in accordance with laser energysettings 126 stored in the memory 124, or other location.

In some embodiments, the controller 122 controls the discharge of thelaser energy 104 through the laser probe 108 using conventionaltechniques. For instance, the controller 122 may control one or moreshutter mechanisms 128 (FIG. 1), which may control the discharge of thelaser energy 104 to the waveguide 106, or the discharge of laser energyfrom individual laser sources of the laser generator 102.

In some embodiments, the system 100 is configured to generate laserenergy 104 in the form of a laser pulse train 130, such as the exemplarylaser pulse train illustrated in FIG. 3. The laser pulse train 130comprises individual laser pulses 132. In some embodiments, the laserpulses 132 each have a short pulse width 134 relative to the laserenergy used for conventional laser lithotripsy procedures, whichtypically has a pulse width on the order of hundreds of microseconds. Insome embodiments, the pulse width 134 of each of the pulses 132 in thetrain 130 is less than or less than 1 ms, for example. In someembodiments, the pulse width 134 is in the range of 1-10,000 ns, 0.1-500μs, or 1 ps-10 ms, for example. Such pulse widths may be obtained usingconventional Q-switched laser rods, such as those mentioned above, orother suitable technique.

In some embodiments, the laser pulses 132 are repeated at a high raterelative to conventional laser systems. In some embodiments, the pulserepetition rate is in the range of 0.001 to 1000 kHz, 1 kHz-2 GHz,greater than 1 GHz, 0.1 Hz-10 GHz. The high pulse repetition rate (GHzrange) covers the life span of plasma clouds, which can enhance thelaser plasma effect to achieve efficient tissue ablation or stonefragmentation.

In some embodiments, the laser generator 102 utilizes multiple lasersources to generate the high pulse repetition rate of the pulse train130. In some embodiments, each of the laser sources is capable ofproducing laser energy that can cause thermal-confined orstress-confined interaction on tissue or a kidney or bladder stone. Thelaser energy or laser pulse trains generated by each of the two or morelaser sources are combined to form the laser energy 104 having thedesired high pulse repetition rate. The laser energy 104 is thendischarged to the targeted object or tissue, such as a kidney or bladderstone 120 through the probe 104.

FIG. 4 is a schematic diagram of an exemplary configuration of the lasergenerator 102 that is configured to generate the laser energy 104 havinga high pulse repetition rate. In some embodiments, the laser generatorcomprises a laser source 140A configured to output laser energy 104A,and a laser source 140B configured to output laser energy 104B. In someembodiments, the laser sources may be Q-switched laser sources or otherconventional devices capable of generating the laser energies 104A and104B each having a pulse width and a pulse repetition rate that is setin accordance with the laser energy settings 126.

In some embodiments, a beam combiner 142 combines the laser energies104A and 104B, such that they overlap into a single laser beam as thelaser energy 104. In some embodiments, the beam combiner 142 comprisesconventional mirrors, lenses and/or other optical components to combinethe laser pulse energies 104A and 104B. More than two laser sources mayalso be combined in this manner to produce pulse trains having highpulse repetition rates. The output laser energy 104 from the beamcombiner 142 is optically coupled to the laser probe 108 for discharge,as shown in FIG. 1.

In one embodiment, the laser energy 104A comprises a laser pulse train144 of laser pulses 146, and the laser energy 104B comprises a laserpulse train 148 of laser pulses 150, as illustrated in the chart of FIG.5. In some embodiments, the pulses 146 and 150 may be of the same ordifferent wavelength, the same or different pulse width, and the same ordifferent pulse shape. In some embodiments the laser pulse trains 144and 148 may have a pulse repetition rate or frequency that is the sameor different. In accordance with some embodiments, the pulses 146 and150 have a wavelength in the range of 400-11000 nm, 300-20000 nm. Insome embodiments, the pulses 146 and 150 have a pulse width in the rangeof, less than 1 μs, 0.1-10000 ns, or 1 ps-10 ms, for example. In someembodiments, the pulse trains 144 and 148 have a pulse repetition ratein the range of 0.1 z-10 GHz.

In some embodiments, the pulses 146 of the pulse train 144 aretemporally offset from the pulses 150 of the pulse train 148 to generatethe pulse train 152 that forms the laser energy 104, as illustrated inFIG. 5. In some embodiments, the pulses 146 and 150 of the pulse train152 do not overlap, as shown in FIG. 5. In some embodiments, the pulses146 alternate with the pulses 150, as shown in FIG. 5.

The laser pulse trains produced by the two or more laser sources of thelaser generator 102 may be temporally offset in any suitable manner. Inone exemplary embodiment, an adjustable delay generator 154 delays thedischarge of the laser pulse train 148 from the laser source 140B inresponse to a trigger 156 received from, for example, the controller 122(FIG. 1). The delay of the triggering of the pulses 150 can be as smallas a few nanoseconds. The trigger signal and the delayed signal may beused to control shutter mechanisms corresponding to the laser sources140A and 140B, for example.

The resultant pulse repetition rate of the pulse train 152 of the laserenergy 104 that can be achieved using the multiple laser sources issubstantially higher than what would be possible using a single lasersource. That is, the laser generator 102 effectively multiplies thepulse repetition rate of a conventional laser source by combining theoutput laser energies of two or more laser sources. Accordingly, thistechnique may be used to produce very high frequency pulse trains 152for the laser energy 104, such as pulse trains having a pulse repetitionrate in the range of up to 2 GHz or more, depending on the width of thepulses (e.g., 146 and 148). As discussed below, this frequency rangeenables the system 100 to match the high estimated natural or resonancefrequencies of urinary or kidney stones to enable more thoroughfragmentation of the stones during laser lithotripsy procedures.

In some embodiments, the laser pulses 146 and 150 of the laser trains144 and 146 are not temporally offset, but directly overlap (i.e.,pulses are synchronized). This allows for the generation of laser energy104 having a higher power than would otherwise be possible using asingle laser source. In some embodiments, the generator 102 isconfigured as described with reference to FIG. 5, but without the delaygenerator 154.

In accordance with another embodiment, the laser generator generateslaser energy 104 in the form of a pulse train 160 shown in FIG. 6, whichis discharged to a targeted stone 120 through, for example, the laserprobe 108. In some embodiments, the pulse train 160 comprises a seriesof pulses 162 at a first power or energy level followed by one or morepulses 164 at a second energy level that is higher than the first energylevel. In some embodiments, the pulses 162 comprise the pulses 146 and150 and form the pulse train 130 in accordance with one or moreembodiments described above. Thus, in some embodiments, the laser pulses162 may be generated using two or more laser sources of the generator102. Exposure of the targeted stone 120 to the pulses 162 heats thetargeted stone 120 and/or produces cracks in the targeted stone 120,while the high energy pulse or pulses 164 pulverize the stone 120.

The pulses 162 and 164 may have the same or different wavelength, pulsewidth or pulse shape. In some embodiments, the pulses 162 have a pulsewidth 134 of approximately less than 1 μus, 1-10000 ns, 1 ps-10 ms. Insome embodiments, the pulses 162 have an energy level of approximately0.01-1000 mJ, 1 nJ-10 J. The pulses 162 are preferably delivered at apulse repetition rate or frequency in the range of 1-20000 kHz, 1 kHz-2GHz, or 0.1 Hz-10 GHz.

In some embodiments, the one or more pulses 164 have an energy level inthe range of 1-10000 mJ, 1 nJ-10 J. In some embodiments, the one or morepulses 164 have a pulse width in the range of less than 1 μs, 1 ns-500μs, 1 ps-10 ms. In some embodiments, the one or more laser pulses 164are generated by a laser source of the laser generator 102 that is notused to generate the laser pulses 162.

In some embodiments, when a train of the laser pulses 164 is used, thetrain of pulses 164 has a lower frequency or pulse repetition rate thanthe train of pulse 162, such as 0.1 Hz-10 GHz. In some embodiments, thelaser pulses 164 have a pulse repetition rate that is tuned to the stone120 targeted for fragmentation, as described below. In some embodiments,the train of pulses 164 has a pulse repetition rate in the range of 1kHz-2 GHz, 0.1 Hz-10 GH. In some embodiments, the train of pulses 164 isformed using a multiple laser source technique in accordance with one ormore embodiments described above with regard to the laser pulse train130.

In some embodiments, the one or more high energy laser pulses 164 occurimmediately after the pulse train of lower energy laser pulses 162. Insome embodiments, the generation of the one or more high energy laserpulses 164 by the generator 102 begins after the targeted stone 120 isexposed to the laser pulses 162, allowing for the one or more laserpulses 164 to overlap the laser pulses 162.

Some embodiments of the invention are directed to methods of producingthe laser energy 104 using the system 100 described above, and laserlithotripsy methods for fragmenting a kidney or bladder stone usingembodiments of the system. In some embodiments, the laser generator 102is configured to output laser energy 104 in accordance with one or moreembodiments described above to fragment a targeted stone 120, such asthat illustrated in FIG. 2.

In some embodiments, the laser energy 104 output from the lasergenerator 102 is defined by laser energy settings 126 stored, forexample, in the memory 124 (FIG. 1) or other location. The laser energysettings 126 may determine the wavelength of the laser energy 104, thepulse width 134 of the pulses that form the laser energy 104, the pulserepetition rate of the laser energy 104, the energy level of the pulsesof the laser energy 104, the duration that the laser energy 104 isoutput (i.e., the duration of the laser treatment), and/or otherproperties of the laser energy 104 output from the laser generator 102.In some embodiments, the controller 122 uses the laser energy settings126 to control the laser generator 102 and its one or more laser sources(e.g., laser sources 140A and 140B) to generate the laser energy 104.

In some embodiments, the laser generator 102 is configured to outputlaser energy 104 that is tuned to fragment the targeted stone 120. Insome embodiments, this tuning of the laser energy 104 matches thefrequency or the pulse repetition rate of the laser energy 104 to anatural or resonant frequency of the targeted stone 120. In someembodiments, this tuning of the laser energy 104 to the targeted stone120 enables the laser energy 104 to more efficiently fragment the stone120, and fragment the stone into smaller particles, than is possibleusing prior art laser lithotripsy techniques.

In some embodiments, the natural frequency of the targeted stone 120 canbe estimated based on characteristics of the targeted stone 120. In someembodiments, the system 100 includes a stone analyzer 170 that isconfigured to determine, or assist in determining, one or morecharacteristics of the stone 120, from which a natural frequency of thestone 120 can be estimated and used to determine the laser energysettings 126. Exemplary stone characteristics include one or moredimensions of the stone, a geometry of the stone, a vibration frequencyof the stone, a composition of the stone, a type of the stone, color ortensile strength, and other characteristics.

In some embodiments, the system 100 includes a mapping or look-up table172 stored in the memory 124 (FIG. 1), or other location that isaccessible by the controller 122. The mapping 172 identifies laserenergy settings for various measured or estimated characteristics of thestone 120. After the controller 122 determines one or morecharacteristics of the targeted stone 120 using the stone analyzer 170,the controller 122 obtains the laser energy settings corresponding tothe one or more determined characteristics using the mapping 172. Thecontroller 122 then sets the laser generator 102, or the individuallaser sources, to generate the laser energy 104 tuned to the stone 120based on the settings. In some embodiments, the laser settings obtainedfrom the mapping 172 are stored as the laser settings 126. The system100 may then perform a laser lithotripsy procedure on the targeted stone120 using tuned laser energy 104 to fragment the stone, as illustratedin FIG. 2.

In some embodiments, the stone analyzer 170 comprises an imager 174configured to capture images of the targeted stone 120, as shown inFIG. 1. The imager 174 may be a conventional imaging component thatcomprises the secondary probe 118 (FIG. 2) in the form of an imagingfiber 176, and an imaging sensor or chip 178, such as a CCD sensor. Insome embodiments, the controller 122 processes images from the imager174 to determine characteristics of a targeted stone 120, such as ameasurement or estimate of the one or more dimensions of the stone 120(i.e., a length such as diameter, area, etc.), the stone's geometry, orother characteristic of the targeted stone 120, for example. In someembodiments, the system 100 includes a display 180 (FIG. 1) on which theimages captured by the imaging sensor 178 may be displayed. In someembodiments, the one or more image-determined characteristics of thestone 120 are mapped in the mapping 172 to laser energy settings (e.g.,a pulse repetition rate, pulse width, etc.) for generating laser energy104 tuned to fragment the targeted stone 120.

In some embodiments, the stone analyzer 170 comprises a Laser DopplerVibrometer (LDV) 182, which is an instrument used to make non-contactvibration measurements of a surface. In some embodiments, the LDV 182exposes the stone 120 to a laser beam, such as the laser energy 104 fromthe laser probe 108, or a laser beam from the secondary probe 118 (FIG.2). A vibration amplitude and frequency of the stone 120 are extractedfrom the Doppler shift of the frequency of the laser beam reflected fromthe surface of the stone 120 in response to the motion of the stonesurface caused by the laser beam. This may be obtained, for example,through the imager 174, or other conventional component. The output ofthe LDV 182 may be a continuous analog voltage that is directlyproportional to the velocity component of the stone surface along thedirection of the laser beam. In some embodiments, the controller 122determines the one or more stone characteristics, such as a vibrationfrequency of the stone 120, based on the output from the LDV 182. Insome embodiments, one or more of these characteristics are mapped in themapping 172 to laser energy settings, such as a pulse repetition rate,for generating laser energy 104 tuned to fragment the stone 120.

In some embodiments, the stone analyzer 170 comprises a Laser InducedBreakdown Spectrometer (LIBS) 184 configured to perform laser inducedbreakdown spectroscopy on a targeted stone 120 through, for example, thesecondary probe 118, and output a spectrometer reading indicative of acomposition of the targeted stone 120. In some embodiments, a strongplasma effect is generated using the laser energy 104, such as the highfrequency pulse train 130 described above. This plasma effect is used bythe LIBS 184 to obtain the composition of the stone 120. In someembodiments, the output composition of the targeted stone 120 is used toidentify a type of the targeted stone 120, a natural frequency (i.e.,vibration frequency) for the stone 120, and/or other characteristics ofthe stone 120. In some embodiments, the controller 122 determines thelaser treatment to be performed to fragment the stone 120 based on theidentified type of stone. In some embodiments, one or more of thesecharacteristics are mapped in the mapping 172 to laser energy settings,such as a pulse repetition rate, for generating laser energy 104 tunedto fragment the stone 120. In some embodiments, the results of the laserinduced breakdown spectroscopy on the targeted stone 120 are also usedfor diagnosis, treatment and recurrence prevention.

Additional embodiments are directed to the use of the system 100 formedin accordance with one or more embodiments described herein to perform alaser lithotripsy treatment to fragment a kidney or bladder stone. FIG.7 is a flowchart illustrating a method of fragmenting a targeted kidneyor bladder stone in accordance with embodiments of the invention. At200, a first laser pulse train, such as pulse train 144 (i.e. laserenergy 104A), comprising first laser pulses 146 is generated using afirst laser source 140A, as shown in FIGS. 4 and 5. At 202, a secondlaser pulse train 148 (i.e., laser energy 104B) comprising second laserpulses 150 is generated using a second laser source 140B. The first andsecond laser pulse trains 144 and 148 are combined into a combined laserpulse train 152 (i.e., laser energy 104) at 204. The combined laserpulse train 152 includes the first and second laser pulses 146 and 150.At 206, the stone 120 is exposed to the combined laser pulse train 152using a laser probe 108, such as illustrated in FIG. 2. At 208, thestone 120 is fragmented in response to the exposure of the stone 120 tothe combined laser pulse train 152.

In some embodiments, step 204 involves temporally offsetting the firstlaser pulses 146 from the second laser pulses 150 to form the combinedlaser pulse train 152 (FIG. 5) or pulse train 130 (FIGS. 3 and 6). Insome embodiments, the first laser pulse train 144, the second laserpulse train 148, and the combined laser pulse train 152 are formed usingthe laser generator 102 described above with reference to FIG. 4. Insome embodiments, the laser generator 102 comprises a delay generator154 that delays the generation of the second laser pulse train 148relative to the generation of the first laser pulse train 144 totemporally offset the first laser pulses 146 from the second laserpulses 150.

In some embodiments, the pulse width 134 of the first and second laserpulses 146 and 150 is in accordance with one or more embodimentsdescribed above. In some embodiments, the combined laser pulse train 152has a pulse repetition rate in accordance with one or more embodimentsdescribed above. In some embodiments, the first and second laser pulses146 and 150 have the same wavelength. In some embodiments, thewavelength of the first laser pulses 146 is different from thewavelength of the second laser pulses 150. In some embodiments, thewavelengths of the first and second laser pulses 146 and 150 are inaccordance with one or more embodiments described above.

In accordance with another embodiment, the laser energy 104 is in theform of a pulse train, such as pulse train 152 (FIG. 5) or the pulsetrain 130 (FIGS. 3 and 6), having pulses (e.g., 132, 162) that are at afirst power or energy level and at a high repetition rate. In someembodiments, these laser pulses are configured to heat and potentiallycrack the targeted stone 120. In some embodiments, the series of laserpulses of the combined laser pulse train 152 or 130 are followed by oneor more high energy pulses 164 (FIG. 6) having a higher energy levelthan the first and second laser pulses, as shown in FIG. 6. In someembodiments of the method, the targeted stone 120 is exposed to the oneor more high energy pulses 164 to pulverize the stone 120. The energylevels of the first and second laser pulses 146 and 150, or pulses 162,and the high energy pulses 164 may be in accordance with one or more ofthe embodiments described above.

FIG. 8 is a flowchart illustrating a method of fragmenting a targetedkidney or bladder stone 120 using laser energy 104 that is tuned to thetargeted stone 120. At 210, an output relating to a characteristic ofthe targeted stone 120 is generated. In some embodiments, the output isgenerated using a stone analyzer 170 in accordance with one or moreembodiments described above. Exemplary embodiments of the characteristicinclude an estimated size of the stone, an estimated length of adimension of the stone (i.e., a diameter of the stone), an estimatedcomposition of the stone, a vibration frequency of the stone, and typeof the stone. In some embodiments, the output relating to acharacteristic of the targeted stone 120 is processed by the controller122 to determine the characteristic of the stone 120.

At 212, laser energy settings are determined based on the output. Insome embodiments, values of the output or the correspondingcharacteristics are mapped to laser energy settings in a mapping 172stored in the memory of the system (FIG. 1), or other location. In someembodiments, the controller 122 uses the mapping 172 to determine thelaser energy settings based on the output.

At 214, laser energy 104 is generated using a laser generator 102 inaccordance with the laser energy settings. Embodiments of the lasergenerator 102 and the laser energy 104 include one or more embodimentsdescribed above. At 216, the targeted stone 120 is exposed to the laserenergy 104 and the stone 120 is fragmented at 218 in response to theexposure.

FIG. 9 is a flowchart illustrating a method of fragmenting a targetedkidney or bladder stone in accordance with embodiments of the invention.At 220, the targeted stone 120 is exposed to first laser energy (laserpulses 162 or pulse train 130) having a first power or energy level. At222, the targeted stone 120 is exposed to second laser energy (one ormore pulses 164) having a second power level. At 224, the stone 120 isfragmented in response to the exposure to the first and second laserenergy. In some embodiments, the second power level is greater than thefirst power level, as shown in FIG. 6. For instance, the first laserenergy may comprise a laser pulse train 130 comprising pulses 162 havinga pulse width and a pulse repetition rate in accordance with embodimentsdescribed above with reference to FIG. 6. For instance, in someembodiments, the first laser energy comprises a laser pulse train 130having a pulse repetition rate in the range of 1 kHz-2 GHz. In someembodiments, the first laser energy heats the targeted stone 120 and/orfacilitates the generation of cracks in the targeted stone 120. In someembodiments, the second laser energy comprises one or more laser pulses164 in accordance with one or more of the embodiments described above.The second laser energy is generally used to pulverize the targetedstone 120 after the targeted stone 120 has been weakened due to itsexposure to the first laser energy.

In some embodiments, step 222 occurs after step 220, as shown in FIG. 6.In some embodiments, step 222 begins after step 220 begins. Here, theremay be some overlap between steps 222 and 220.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

1-20. (canceled)
 21. A system comprising: a first laser sourceconfigured to generate a first laser energy; an analyzer configured toreceive feedback based on the first laser energy from a target object,and generate an output relating to a characteristic of the targetobject; and a controller configured to determine the characteristic ofthe target object based on the output from the analyzer, and determine afirst laser energy setting based on the characteristic of the targetobject.
 22. The system of claim 21, further comprising a laser probeconfigured to discharge the first laser energy towards the targetobject.
 23. The system of claim 21, further including a second lasersource configured to generate a second laser energy.
 24. The system ofclaim 23, wherein a power level of the second laser energy is greaterthan a power level of the first laser energy.
 25. The system of claim23, further including a beam combiner configured to combine the firstlaser energy and the second laser energy into a single output laserenergy.
 26. The system of claim 23, wherein the first laser energyincludes a first laser pulse train with a first pulse repetition rate,the second laser energy includes a second laser pulse train with asecond pulse repetition rate, and the first laser energy and the secondlaser energy are discharged at different times.
 27. The system of claim21, wherein the output includes at least a size of the target object, alength of the target object, a composition of the target object, or avibration frequency of the target object.
 28. The system of claim 23,wherein the first laser energy setting and the second laser energysetting are determined based on the characteristic of the target object.29. The system of claim 21, wherein the target object is a kidney stoneor a bladder stone.
 30. A controller for a system, the system includinga first laser source and an analyzer, wherein the controller isconfigured to: instruct the first laser source to generate a first laserenergy; control the analyzer to receive feedback based on the firstlaser energy from a target object and to generate an output relating toa characteristic of the target object; determine the characteristic ofthe target object based on the output from the analyzer; and determine afirst laser energy setting based on the characteristic of the targetobject.
 31. The controller of claim 30, wherein the controller isconfigured to control the first laser source to generate the first laserenergy with a first laser pulse train and a first pulse repetition rate.32. The controller of claim 30, wherein the controller is configured tocontrol a second laser source to generate a second laser energy with asecond laser pulse train and a second pulse repetition rate.
 33. Thecontroller of claim 32, wherein a power level of the second laser energyis greater than a power level of the first laser energy.
 34. Thecontroller of claim 32, wherein the controller is configured to controlthe system to combine the first laser energy and the second laser energyinto a single output laser energy.
 35. The controller of claim 32,wherein the controller is configured to delay discharge of the secondlaser energy.
 36. The controller of claim 34, wherein the controller isfurther configured to cause the system to output a laser energy pulsehaving an energy level greater than the single output laser energy afterthe single output laser energy is output from the system.
 37. Thecontroller of claim 32, wherein the controller is configured todetermine the first laser energy setting and a second laser energysetting based on the characteristic of the target object.
 38. A methodcomprising: generating, with a first laser source, a first laser energy;receiving, at an analyzer, feedback based on the first laser energy froma target object; generating, with the analyzer, an output relating to acharacteristic of the target object; receiving, at a controller, theoutput relating to the characteristic of the target object from theanalyzer; determining, with the controller, the characteristic of thetarget object based on the output; and determining, with the controller,a first laser energy setting based on the characteristic of the targetobject.
 39. The method of claim 38, further comprising: discharging,with a laser probe, the first laser energy towards the target object.40. The method of claim 38, further including: generating, with a secondlaser source, a second laser energy; and combining, with a beamcombiner, the first laser energy and the second laser energy into asingle output laser energy.